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Definition
LabTALK is an interpreter language based on the BASIC language. The task of this document is not to teach BASIC, but rather to point out the similarities and differences between it and LabTALK. Therefore the documents below assume that you have some general programming knowledge. Variables LabTALK can work with integer, float and string variables. There is no forward declaration of variables like in advanced languages (C, or Pascal..) The variable becomes the type as soon as you assign a value to it for first time. a = 10 will create integer variable 'a' b = 10.5 will create float variable 'b' name = "Hello!" will create string variable 'name'. If you need to enter '\' you need to do it like in the C language with double '\\' file = "c:\\myfile.txt" You can create your very first program quite easily: string = "Hello!" print string Then hit the Run button and watch the output tab: Arrays Arrays don't have to be declared as to type or number of elements. They all could be integer, float or string. myarray0 = 10 myarray1 = 20 Arrays in LabTALK can go even to negative: myarray-1 = 10 is still valid. In fact you can mix various types within one array - but of course this is not advised and is of little benefit. The array index may be a constant, another variable or an expression. See the code below: a = 5 myarraya = 10 myarraya+1 = 20 print myarray6 The printed result is of course 20. Expressions LabTALK has fully developed integer and float expressions. b = 3 a = 3 + 2 * 5 + 4*(10+b*(23+b)) print a The result is 365. You can use expressions directly in any function. String operations LabTALK can use various string operations as well. See the code below: c = "Os"+"car" str = "Hello"+ CHR(32) + c + "!" print str Result is: Hello Oscar Comments Everything in a line after // is deemed to be a comment menu = MenuGetCurSel() // VTS menu 1..255, VMG menu 10001..10255 Whole line can be just a comment // ****** The loop starts here ******** You can comment block of the text with /* and */ /* This text is just a comment It will never run */ Language. The whole language can be divided into two parts. One are commands of the basic language - the definition of the language. The other part are functions that are specific to DVD-lab. CORE of language Commands Syntax example Description for to next for x=1 to 10 ... next x loop, can be nested if then else endif if (x 0) then ..... else ...... endif condition, can be nested print print "Variable ", a, "Other Variable ", b print to Output window or if run directly show a message print msg print msg "Variable ", a always show a message trace trace "Variable ", a print only to output window, if run directly nothing is shown (good for debugging) input input "Enter value", a Input box for multiple parameters end End of the script goto goto 100 got label 100 gosub gosub 100 goto subroutine label 100 return return from subroutine Defined functions Functions Syntax example Description RND a = RND(5) random value 0...5 INT a = INT(b) integer value from float FLOAT a = FLOAT(b) create float from integer CHR c = CHR(32) generates character from ascii number (32 is space for example) ABS a = ABS(b-5) absolute value STR c = STR(5) Convert integer number to string. In our example the C will become c= "5" sin a =sin(3.14) Sine cos a =cos(3.14) Cosine MIN a = MIN(b,c) minimum value from two parameters MAX a = MAX(b,c) maximum value from two parameters RGB color = RGB(255,0,0) color value from red, green, blue components (in our example result is red color) GETR GETG GETB red = GETR(color) Get red, green or blue component from color value VMG firstVMGmenu = VMG(1) adds 10000 to the parameter. For menu coding, see more functions LEFT string = LEFT(input, x) gets first x character from left of the input string RIGHT string = RIGHT(input, x) gets first x character from right of the input string LOW string = LOW(string1) convert the string to lowercase Predefined Values TRUE FALSE 1 0 NULL 0